MB-6582 Clones Cores at Startup, with No Buttons Pressed?

[dwestbury]

I'm experiencing a strange issue where my MB-6582 comes up from a cold start and instantly begins cloning it's cores, without me holding down the menu button.

Then, once booted, it drops into the oscillator config page and freezes there, completely unresponsive to any buttons or knobs. 

 

 

 

I assume it's a bad connection or short somewhere in the core1 and/or control surface signal path, so here's what I've tried so far:

> completely removed the ICs from U16 - U23 in case they were causing whacky feedback, but no change

> exhaustively searched for shorts and bad solder joints all around U1_CORE1 (all seems OK)

> multimeter continuity and resistance testing for each socket pin, above and below the base PCB (all continuity seems OK, with resistance levels between .2 -.3 ohms on each pin) 

> multimeter testing for each core1 component: 

	Designator	Description	Component type used	Notes
	C1_CORE1	Capacitor - MLCC	33pF	OK
	C2_CORE1	Capacitor - MLCC	33pF	OK
	C3_CORE1	Capacitor - MLCC	100nF	OK
	D1_CORE1	Diode	1N4148	OK
	Q1_CORE1	Crystal	10MHz	10 Mhz, confirmed with Oscilloscope
	R1_CORE1	Resistor	100 Ohm 1/4W 1%	OK
	R10_CORE1	Resistor	10K 1/4W 1%	OK
	R12_CORE1	Resistor	1K 1/4W 1%	OK
	R2_CORE1	Resistor	1K 1/4W 1%	OK
	R6_CORE1	Resistor	1.2K 1/4 1%	Reads @ 299 Ohms from each core
	R9_CORE1	Resistor	10K 1/4W 1%	OK

 

Appreciate any suggestions or guidance..

Cheers

 

Edited May 7, 2020 by dwestbury

[Noise-Generator]

Well this is he third issue I also had but forget how to solved this ;)

But I'm kind of sure it was a short - located at the bankstick area and connections.

[dwestbury]

19 hours ago, Noise-Generator said:

Well this is he third issue I also had but forget how to solved this ;)

But I'm kind of sure it was a short - located at the bankstick area and connections.

Appreciate the general guidance...

I haven't looked at this in a few days, but will hover around the banksticks later this week.

 

Cheers,

-Darrell